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<!DOCTYPE html><html lang="en"dir="ltr"><head><meta charset="UTF-8"><meta name="viewport"content="width=device-width,height=device-height,initial-scale=1,minimum-scale=1,shrink-to-fit=no"><meta http-equiv="X-UA-Compatible"content="ie=edge"><meta name="theme-color"content="#ffffff"><meta name="apple-mobile-web-app-status-bar-style"content="#ffffff"><meta name="generator"content="Jekyll v4.0.1"><meta name="author"content="The GTK Team"><meta name="keywords"content="gtk, gtk, gimp, gnome, toolkit, user interface"><title>The GTK Project - A free and open-source cross-platform widget toolkit</title><meta itemprop="description"name="description"content="GTK is a free and open-source cross-platform widget toolkit for creating graphical user interfaces."><meta property="og:locale"content="en_US"><meta property="og:type"content="article"><meta property="og:title"content="The GTK Project - A free and open-source cross-platform widget toolkit"><meta 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rel="icon"type="image/png"sizes="16x16"href="https://www.gtk.org/assets/img/icons/favicon-16x16.png"><link rel="canonical"href="https://www.gtk.org/docs/apis/index"><link rel="stylesheet"href="https://www.gtk.org/assets/@fortawesome/fontawesome-free/css/all.min.css"type="text/css"media="screen"><link rel="stylesheet"href="https://www.gtk.org/assets/css/markdown.css"type="text/css"media="screen"><link rel="stylesheet"href="https://www.gtk.org/assets/css/theme.css"type="text/css"media="screen"><link rel="stylesheet"href="https://www.gtk.org/assets/css/colorful.css"type="text/css"media="screen"><link rel="stylesheet"href="https://www.gtk.org/assets/css/index.css"type="text/css"media="screen"></head><body><header class="navbar small bg-dark"><nav class="container navbar-expand-md px-0 px-md-3"><a href="https://www.gtk.org"class="navbar-brand text-white"><img src="https://www.gtk.org/assets/img/logo-gtk-sm.png"class="pr-2"style="max-width:40px;"><strong>GTK</strong></a> <a class="btn navbar-toggler border-0 bg-white"role="button"data-toggle="collapse"data-target="#navbarSupportedContent"href="#"><i class="fas fa-ellipsis-h text-dark"></i></a><div class="collapse navbar-collapse"id="navbarSupportedContent"><ul class="navbar-nav ml-auto"><a href="https://www.gtk.org/features/"class="nav-link-dark float-right text-white rounded">Features</a> <a href="https://www.gtk.org/docs/"class="nav-link-dark float-right text-white rounded">Docs</a> <a href="https://www.gtk.org/community/"class="nav-link-dark float-right text-white rounded">Community</a> <a href="https://gitlab.gnome.org/GNOME/gtk/"target="_blank"class="nav-link-dark float-right text-white rounded">Code</a> <a href="https://blog.gtk.org/"target="_blank"class="nav-link-dark float-right text-white rounded">Development Blog</a></ul></div></nav></header><button class="d-none btn border border-info bg-white rounded-circle position-fixed"id="btn-go-to-top"><i class="fas fa-angle-up"></i></button><section><div class="container"><div class="row"><div class="col-md-3 small p-0 nav-side"id="mySidenav"><div class="text-break bg-white p-0 pt-2 pt-md-4 h-100"><a href="#"class="btn d-md-none btn-close mt-2"onclick="closeSideNav()"><i class="fas fa-times fa-halfx"></i></a><ul class="list-group"><li class="list-group-item border-0 group-header pb-4"><a href="https://www.gtk.org/docs/getting-started/"class="text-dark"><i class="fas fa-cogs fa-fw"></i> <strong>Getting Started</strong></a><ul class="list-group"><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/getting-started/hello-world/"class="text-muted stretched-link">Hello World</a></li></ul></li><li class="list-group-item border-0 group-header pb-4"><a href="https://www.gtk.org/docs/installations/"class="text-dark"><i class="fas fa-box-open fa-fw"></i> <strong>Installations</strong></a><ul class="list-group"><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/installations/linux/"class="text-muted stretched-link">Linux</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/installations/macos/"class="text-muted stretched-link">Macos</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/installations/windows/"class="text-muted stretched-link">Windows</a></li></ul></li><li class="list-group-item border-0 group-header pb-4"><a href="https://www.gtk.org/docs/language-bindings/"class="text-dark"><i class="fas fa-random fa-fw"></i> <strong>Language Bindings</strong></a><ul class="list-group"><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/language-bindings/cpp/"class="text-muted stretched-link">Cpp</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/language-bindings/guile/"class="text-muted stretched-link">Guile</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/language-bindings/javascript/"class="text-muted stretched-link">Javascript</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/language-bindings/python/"class="text-muted stretched-link">Python</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/language-bindings/rust/"class="text-muted stretched-link">Rust</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/language-bindings/vala//"class="text-muted stretched-link">Vala</a></li></ul></li><li class="list-group-item border-0 group-header pb-4"><a href="https://www.gtk.org/docs/dev-tools/"class="text-dark"><i class="fas fa-tools fa-fw"></i> <strong>Dev Tools</strong></a><ul class="list-group"><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/dev-tools/eclipse/"class="text-muted stretched-link">Eclipse</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/dev-tools/gnome-builder/"class="text-muted stretched-link">Gnome Builder</a></li></ul></li><li class="list-group-item border-0 group-header pb-4"><a href="https://www.gtk.org/docs/apis/"class="text-dark"><i class="fas fa-cubes fa-fw"></i> <strong>API References</strong></a><ul class="list-group"><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://docs.gtk.org/gtk4/"class="text-muted stretched-link">GTK</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://docs.gtk.org/gdk4/"class="text-muted stretched-link">GDK</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://docs.gtk.org/gsk4/"class="text-muted stretched-link">GSK</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://docs.gtk.org/gdk-pixbuf/"class="text-muted stretched-link">GdkPixbuf</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://docs.gtk.org/Pango/"class="text-muted stretched-link">Pango</a></li></ul></li><li class="list-group-item border-0 group-header pb-4"><a href="https://www.gtk.org/docs/architecture/"class="text-dark"><i class="fas fa-vector-square fa-fw"></i> <strong>Architecture</strong></a><ul class="list-group"><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/architecture/glib/"class="text-muted stretched-link">Glib</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.gtk.org/docs/architecture/pango/"class="text-muted stretched-link">Pango</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.cairographics.org/documentation/"class="text-muted stretched-link">Cairo</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.opengl.org/"class="text-muted stretched-link">OpenGL</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://www.vulkan.org/"class="text-muted stretched-link">Vulkan</a></li><li class="list-group-item border-0 p-0 py-1 padding-icon"><a href="https://wayland.freedesktop.org/"class="text-muted stretched-link">Wayland</a></li></ul></li></ul></div></div><div class="col-md-9 py-4 px-sm-4 bg-light border-0 border-md-left"><div class="d-flex flex-sm-row flex-column py-3 py-md-0 app-shadow"><div class="w-100"><button class="btn btn-mdcolor btn-sm d-inline-block d-md-none"onclick="openSideNav()"role="button"><i class="fas fa-bars fa-fw pr-2"></i>More Topics</button><nav aria-label="breadcrumb"><ol class="breadcrumb small bg-transparent pl-0 m-0"><li class="breadcrumb-item"><a href="https://www.gtk.org/docs/">Docs</a></li><li class="breadcrumb-item active"aria-current="page">Apis</li></ol></nav></div></div><article class="markdown-body my-4"><p>GTK provides, directly or through various dependencies, a full platform for application development.</p><p>You can browse the latest available documentation <a href="https://docs.gtk.org">online</a>.</p><p>You can find guides and tutorials on the <a href="https://developer.gnome.org/documentation/">GNOME developer documentation website</a>.</p><h3 id="user-interface-and-display">User interface and display</h3><ul><li><a href="https://docs.gtk.org/gtk4/">GTK</a> — Widget toolkit for graphical interfaces</li><li><a href="https://docs.gtk.org/gdk4/">GDK</a> — Low-level abstraction for the windowing system</li><li><a href="https://docs.gtk.org/gsk4/">GSK</a> — Low-level scene graph and 3D rendering API</li><li><a href="https://docs.gtk.org/Pango/">Pango</a> — International text rendering with full Unicode support</li><li><a href="https://www.cairographics.org/manual/">Cairo</a> — 2D, vector-based drawing for high-quality graphics</li><li><a href="https://docs.gtk.org/atk/">ATK</a> — Accessibility toolkit to implement support for screen readers and other tools (GTK3 only)</li></ul><h3 id="storage-of-the-users-data">Storage of the user’s data</h3><ul><li><a href="https://docs.gtk.org/gio/class.Settings.html">GSettings</a> — Configuration storage for application preferences</li></ul><h3 id="file-access">File access</h3><ul><li><a href="https://docs.gtk.org/gio/iface.File.html">GFile</a> — File and URI handling, asynchronous file operations, volume handling</li></ul><h3 id="networking">Networking</h3><ul><li><a href="https://docs.gtk.org/gio/class.SocketClient.html">GNetworking</a> — Networking and sockets API with streams</li><li><a href="https://libsoup.org/libsoup-3.0/index.html">Soup</a> — Asynchronous HTTP library with cookies, SSL, and XML-RPC</li></ul><h3 id="multimedia">Multimedia</h3><ul><li><a href="https://gstreamer.freedesktop.org/documentation/gstreamer/gi-index.html">GStreamer</a> — Playing, mixing, and manipulating sound and video</li><li><a href="https://docs.gtk.org/gdk-pixbuf/">GdkPixbuf</a> — Loading icons and other graphical assets</li></ul><h3 id="inter-process-communication">Inter-process communication</h3><ul><li><a href="https://docs.gtk.org/gio/class.DBusProxy.html">D-Bus</a> — Inter-process communication bus to provide APIs to other processes</li><li><a href="https://www.freedesktop.org/software/polkit/docs/latest/">Polkit</a> — Access control for system-level services provided through D-Bus</li></ul><h3 id="asynchronous-tasks">Asynchronous tasks</h3><ul><li><a href="https://docs.gtk.org/gio/class.Task.html">GTask</a> – Cancellable synchronous or asynchronous task and result</li></ul><h3 id="application-support">Application support</h3><ul><li><a href="https://docs.gtk.org/gio/class.Application.html">GApplication</a> — Writing applications</li></ul><h3 id="foundational-c-utilities-and-object-system">Foundational C utilities and object system</h3><ul><li><a href="https://docs.gtk.org/glib/">GLib</a> — Data structures and utilities for C programs</li><li><a href="https://docs.gtk.org/gobject/">GObject</a> — C-based object and type system with signals and slots</li></ul></article><div class="bg-white p-3 border rounded shadow-sm small"><i class="fas fa-edit text-info fa-fw pr-2"></i> <span>Observed a typo or some missing information, <a href="https://gitlab.gnome.org/Teams/Websites/www.gtk.org/tree/master/_docs/apis/index.md">edit this page</a>.</span><br><i class="fas fa-plus-square text-info fa-fw pr-2"></i> <span>Read on <a href="https://gitlab.gnome.org/Teams/Websites/www.gtk.org/tree/master/CONTRIBUTING.md/">how to contribute</a> to this website.</span></div></div></div></div></section><script src="https://www.gtk.org/assets/jquery/dist/jquery.min.js"></script><script src="https://www.gtk.org/assets/popper.js/dist/umd/popper.min.js"></script><script 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